Mock-Server - Custom object as REST response

Question

I'm using Mock-Server (mock-server.com) in version 5.10.0 for mocking a REST-API in a JUnit 5 test. I'm developing a spring-boot application with Java 8. My payload format is "protobuf" and so my REST interface is returning a ResponseEntity<MyProtoObject>. Unfortunately I can't find a built-in solution in Mock-Server that custom objects are returned by the Mock-Server as body. I only found methods like withBody(String) or withBody(byte[]). In addition to that methods I found a method withBody(BodyWithContentType). I tried to create the following implementation/usage of the abstract class BodyWithContent<T> in my unit testclass:

private final class MyProtoObjectPayloadBody extends BodyWithContentType<MyProtoObject> {

    public MyProtoObjectPayloadBody () {
        super(null, null);
    }

    @Override
    public MyProtoObject getValue() {
        // return logic of MyProtoObject
    }
}

// Called in @BeforeEach
private void prepareMock() {

    this.mockServer.when(HttpRequest.request().withMethod("GET").withPath("/my-path"))
                .respond(HttpResponse.response().withStatusCode(200).withBody(new MyProtoObjectPayloadBody ()).withDelay(TimeUnit.SECONDS, 5));
}

When I debug my code where the ResponseEntity occurs I get the response from the mock server but the "body" of the response is always empty. My custom getValue() is never called, too. I ensured that the REST call result in my application logic comes from the mock server using different return codes.

Can someone help me with this problem?

Answer 1

Unfortunately I got the reply from the mock-server developer via Slack that it's not possible to return custom objects. It's unclear to the mock-server how they should be (de)serialized. So I'll try to use a workaround via byte[]